Apparatus for heating furnaces or kilns.



W. R. DUNN.

APPARATUS FOR HEATING FURNACES OR KILNS.

APPLI'GATION FILED AUG.25, 1909.

Patented Jan. 2, 1912.

- Lmw.

nvvEN'roR WITNESSES ATTORNEY UNITEA STATES PATENT oEEIcE.

WILLIAM a.. DUNN, or EASTON; PENNSYLVANIA.

APPARATUS FOR HEATING FURNACESOR KILNS.

' Specification of Letters Patent.

Patented Jan. 2,1912.

Application led August 25, 1909. Serial No. 514,498.

To all rwhom t may concern,| Y

' Be it known that I, WILLIAM R. DUNN, a citizen of the United VStates of A merica, residing in Easton', in the county of' North'- ampton, in the State of Pennsylvania, have invented a certain new and useful Improvement in Apparatus for Heating Furnaces or Kilns,.of which the following, is a' true and exact description, reference being had to the accompanying drawing, which .forms a part thereof.

My present invention relates to the means employed for heating furnaces or kilns of the type in which the fuel employedis pulverized coal and is blown into the combustion chamber of the furnace or kiln by an air blast, and the invention is particularly adapted for use in connection with the elongated rotary kilns of the kind usedin the manufacture of hydraulic cement. y

-The object of the invention .is to improve the means employed for heating furnaces or kilns of the type specified; in' part, by providing simple and effective means by which the character of the fla-me and its ocation can becontrolled and .regulated to respond `to the varying conditions 'with which the' ,furnace may operate; and in part, by the provision ofq novel means bywhich the air passing into the combustion .chamber with f Athe powdered vcoal is preheated.

the kiln ofthe usual 'The various features of novelty which characterizevmy invention are pointedout with particularity in the 'claims'annexed'to and forming a part of this specification.'

Fpr abetter understanding of the invention,

however, and the advantages possessed byit,

-reference should be had tothe accompanydrawings and descriptive matter 1n which I haveillustrated and described one i of the forms in'which the invention ymay be embodied. i

l The one 'ligure' ofthe drawing`jshown is Va sectional elevation of a portion offa'rctary kiln and the mechanism fori-blowing pow,- dered fuel into the kiln. y I

In the drawing, A represents thebody of long'ated rotarytype,

slightly inclined tothe horizontal, in com-v.l

mon use in the manufacturev of hydraulic cement.

- B represents the end wall'of the kiln at the end-where the fuel isy admitted... The.

end wall B has aperforation formed through 1t c omprisinga. cylindrical outer portion B which is located' substantially in of the perforation through the end wall', vis located a hollow member E terminating in a cylindrical portion E over which is fitted telescopic fashion a pipe section or conduit memberD which extends into the aperture B with its inner end in proximity to the inner end of the cylindrical perforation portion B. The pipe D may be axially adjusted to vary .the position of its inner end relative to` the inner surface of the wall B by means of a hand lever F pivotally con'v nected to the pipe D atA D, and pivotally connected to an arm E2 rojecting, from the body of the member In the form vshown the fuel is blown into the member E through a pipe section L projecting through the outer endwall Es of the mem-- pber` E. The pipe section` L is appreciably signaller than the internal dian'ieter` of the, 'bod'y of the ymemberY E and the la-t'ter'lhas ,connected to ita conduit g, the lower end of which projects into the mouth Dzo'fthe clinker pit.

` The mechanism employed forblowing the lpowdered. coal through thel ltube L may be of anylsuitable forni, though I prefer'the mechanism shown, which, however,forms no ypartv of the present' invention, but on the contrary isjdescribed andclaimed vlin'. my

,'PatentNo-f-95'4a944, granted April 12, 1910.

.This appara-tus comprises a hopperl H from which the'powderedcoal 1s carried at a reguy'lated,rate'throu'gh a pipe section IY-by means .bf arotaryconveyer J having spirall con- 'veyer 'y ribs J. The pipe Iv communicates 4with the cylindrical chamber K3 of a housthe chamber K4 through which -they pass.

more or less slowly into the pipe section L. Anair blast nozzle M projects into the pipe L and may be connected to any suitable air moving device (not shown),- for supplying air at the necessary pressure to carry the coal out of the pipe section L and through the section L which forms an extension of the pipe section L into the chamberE. The

'stream of air and coal passing into the chamber E from the pipe section L has sufficient. velocity to cause a considerable additional amount yof air to be drawn into the chamber E through the conduit g. The air drawn through the conduit is drawn from the mouth of the cylinder pit and of course is highly heated. In consequence, the air and coal passing into the kiln proper is preheated to an. advantageous extent which'l facilitates the proper and efficient combus- 30 tion of the coal within the kiln. The combustion of the coal, those skilled in lthe art will understand, begins when it is heated to.

a certain temperature known as the temperature of ignition. The pipe section D is formed usually, if not always, of metal, and in any case is necessarily maintained at a substantially lower temperature than the inner surface including the conical wall B.2 of the furnace end wall B to prevent the section D from being destroyed by the heatto which it is subjected. Preferably, as shown, the member D does not entirely fill the perforation portion B', but has its outer surface separated from the inner curved surface of the perforation portion so that a cooling film of air may be drawn into the furnace along the outer surface of the pipe section D. .When the pipe D extends into the furnace beyond the inner end of aperture portion D', the air and coal issuing from the pipe D is less quickly heated than when the air and coal issue from the pipe D in close proximity to the Wall of the conical aperture portion B2. In consequence, the adjustment of the pipe section D determines the point in the kiln at -which combustion begins, and I have, found in actual operation that the shape of the ame is also effected by the ad- Ajustme'nt of the member D. When this member is projected into the furnace some distance beyond the aperture portion B?-the flame is actually longer, that 1s, combustion proceeds less rapidly and is continued in a portion of the furnace more remote from thel end wall B, than when the pipe D projects a shorter distance into the kiln. I have also found that the adjustment of the pipe D which will give the best results under one condition of operation will not give the best results under different conditions of operation. Among the varying conditions which I find need to ibe compensatedvfor 'by adjusting the pipe. D, arefthe temperature at the mouth of the clinker pit when thelconnection g is employed, the stack pressure, the pressure of the air'passing through the nozzle or pipe D, the pressure of, and moisture contained in, the atmosphere, and the character of the coal, that is its dryness and neness.

The arrangement shown for preheating the blast and fuel possesses important advantages because of the relative shortness of the. pipe g and consequent small frictional oppositionl to the passage of hot airthrough it, and also because the hot air from the clinker pit is admixedwith the blast and fuel in close proximity to the point of discharge into the kiln. In consequence there is little waste of heat of the air drawn from the clinker pit through conduction or radiation and no mechanism is subjectedto the action of hot air and gases drawn from the clinker pit. Which arey o'f a character to be injured thereby. a

In accordance with the provisions of the statutes I have herein described the best form of my invention now known to me. It will be readily apparent to those skilled in 'the art, however, that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention, and that certain features of the invern tion claimed may be advantageously elnployed under some circumstances without a corresponding use of other features, and I do not wish the claims hereinmade to be limited to the particular form of apparatus hereinafter disclosed more than is made necessary -by the state of the art.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is:l

1. The combination with the wall of a kiln having a perforation through it, comprising a cylindrical outer portion and a conical inner portion, of means for blowing powdered fuel and air into the kiln through said perforation, including a pipe section or burner nozzle vextending into said perforation and adjustable in the direction of its length to vary the relation between the inner end of the section and the inner surface of the kiln wall, ysaid burner nozzle having its outer surface separated from the inner wall of said perforation by a space through which air may pass into saidkiln.

2. In a cement kiln, the combination with the kiln proper and the clinker pit, of means for blowing powdered coal into the kiln,

surrounding said nozzle, a' burner nozzle ex.-

1,o1a,a79 i v 8 comprising in 'combination' a f blast nozzle direction of its length, and lay conduit exthrough lwhich air under pressure admixed ternal to the kiln leading directly from the with the powdered coal issues, a chamber 'clinke'r'pit to said chamber.`

l i WILLIAM R. DUN N.. 5 tending into the kiln through which the fuel 'Witnesses: may be blown from said chamber into said S. WARREN HAR'iwnLL,l kiln, means for adjusting said nozzle in the CHAs. B. BRUNNER. 

